The use of medical consumable items is of significant importance in the field of medicine and medical technology. Thus, by way of example, in medical diagnostics and analysis and in medical therapeutics, in many cases medical devices are used which, for example, have a diagnostic, analytical or therapeutic function and rely on one or more medical consumable items in order to carry out this function.
Examples of such medical systems are medical analysis devices which are used for the quantitative and/or qualitative detection of at least one analyte in a sample, for example for the detection of one or more metabolites in a body fluid. Glucose measuring devices shall be mentioned here as an application example, these devices being used to measure a glucose content for example in blood, interstitial fluid, saliva or urine.
Such analysis devices or others generally use one or more test elements by means of which the quantitative and/or qualitative detection of the analyte is effected. By way of example, said test elements can comprise one or more test fields which, upon contact with the analyte, carry out a specific chemically or physically detectable reaction or experience a specific, measurable change. Accordingly, the analysis devices can be designed to determine the analyte concentration optically, electrochemically or in some other way with the test elements. The test elements can be present, for example, as small test tubes, test strips, test tapes, test wheels having test fields arranged on a top side and/or a circumference, foldable test papers having a plurality of test fields, or in some other form. In this case, the test elements can be present individually or, for example, as a plurality in magazine form, where in the latter case a magazine with the test elements can also be regarded as a consumable item.
Another example of such medical systems with consumable items is lancet systems, in which, for example, a puncture aid functions as a medical device. Said puncture aid is generally designed to perforate part of a patient's skin by means of one or more consumable items in the form of lancets in order, for example, to generate a sample of blood or interstitial fluid.
Further examples of such medical systems are medication systems with metering devices. Such metering devices generally even operate with a plurality of types of medical consumable items. Thus, firstly, it is possible to use, for example, cartridges or other supply vessels of a medicament which is metered by means of the metering device. In this case, the medicament itself and/or the medicament with the corresponding vessel (for example the cartridge) can be regarded as a consumable item. One example of such metering devices is medication pumps, such as insulin pumps, for example. However, these metering devices generally furthermore require further types of medical consumable items, in particular catheters, for example.
Numerous further types of medical systems of this type, comprising a medical device and at least one consumable item, are known. One challenge for these medical systems, in practice, is that the medical device, in order to be able to interact with the consumable item correctly in order to carry out its medical function, requires information that can change. Thus, by way of example, test elements can differ from batch to batch, such that a batch-specific information component can be required for the correct evaluation of the quantitative and/or qualitative detection of the at least one analyte in the sample. This can be, for example, information about how the optical luminescence or absorption properties, i.e. e.g. the luminescence or color of a test field of a test element, changes with the analyte concentration. Electrochemical evaluation information components can also be encompassed. By way of example, current profiles and/or electrical potentials are measured in this case.
In the case of lancet systems, for example lancet systems with consumable items in the form of a lancet magazine having a plurality of lancets or in the form of an individual lancet, a puncture aid, for example, can require information about whether a correct type of consumable item has been inserted into the puncture aid, for example a lancet of a correct manufacturer or type. Generally, such information in the case of this type of consumable items or other types of consumable items can for example also be used for protection against counterfeiting in order to differentiate items of a correct or authorized manufacturer from “counterfeit” consumable items. This last, in addition to avoiding economic damage, can greatly reduce the risk of damage to health caused by counterfeit medical products.
In the case of medical systems comprising metering devices, for example insulin pumps, information about the type and/or the content of a cartridge of a medicament may be required, for example. If catheters or cannulas are used to meter the medicament, then a filling volume of the catheter may be required, for example, in order to ensure correct initial filling or flooding (“priming”) of the catheter.
These are just a few examples of information components which can or have to be exchanged in the case of such medical systems. To solve this problem there are various possibilities in the prior art. Thus, in the case of commercially available glucose measuring devices, for example, an information carrier, for example a so-called ROM key, is enclosed with each batch of new test elements. The patient is required to enter said ROM key into the analysis device before using the new batch, such that correct information can be used for the evaluation of the measurement. However, this technique is associated with the risk, in principle, that, precisely in the case of older patients or children, the exchange of the ROM key fails to occur upon use of a new batch on the test strip. This can, since in this case possibly incorrect measurement results are output, have consequences with regard to an erroneous medication based on the erroneous measurement results.
The prior art therefore discloses various medical systems in which directly on the consumable material, that is to say not as a separate information carrier but rather fixedly connected to the consumable material, such an information carrier is provided. Since these information carriers, on account of a constantly increasing cost pressure in the medical sector, have to be completed in a cost-effective fashion and furthermore in a very small fashion, known electronic information carriers (such as radiofrequency labels for example) are ruled out in many cases.
Therefore, medical systems are known in which two- or three-dimensional optical codes are applied to medical consumable items, which can be read in by means of a corresponding optical code reader of the medical device. See, for example, U.S. Pat. No. 6,588,670 B2, the disclosure of which is hereby incorporated herein by reference in its entirety. Test strips equipped with corresponding barcodes as optical codes are also known. See, for example, U.S. Pat. No. 4,476,149 and U.S. Pat. No. 6,168,957, the disclosures of which are hereby incorporated herein by reference in their entireties. Reference may hereinafter be made to such optical codes by way of example.
One difficulty in the case of such optical codes have is that, in particular in medical handheld devices, the structural space available for the code reader is extremely limited. Moreover, the code readers have to be constructed in a very light fashion and have to be able to be manufactured cost-effectively in mass production. Numerous code readers for reading out optical codes are known from the prior art. See, for example, US 2006/0213994 A1 (code readers for DNA microarray scanners) and U.S. Pat. No. 7,175,091 B2 (code readers for check card readers), the disclosures of which are hereby incorporated herein by reference in their entireties.
Optically resolving proximity sensors, in particular in the form of so-called contact imaging sensors (CIS) are known from other fields of the art. For example, a thin image sensor is in the prior art in which an image of the object is generated on an image sensor by means of a microlens array. See, for example, US 2008/0088731 A1, the disclosure of which is hereby incorporated herein by reference in its entirety. Also, a fingerprint sensor is known in which a projection onto a CCD/CMOS structure is likewise effected by means of a microlens array. See, for example, US 2006/0202104 A1, the disclosure of which is hereby incorporated herein by reference in its entirety.
However, such code readers or image sensors have several disadvantages for use in medical systems of the type described above. This is because many of said sensors, in particular owing to the use of microlens arrays, necessitate a comparatively large structural space. Moreover, the production outlay for microlens systems is considerable, and the resolution of such microlens systems is generally inadequate for very small optical codes such as are required on test strips, for example.
In this case, one particular problem is posed in particular by the illumination required for many code readers. Illumination through a medical consumable item cannot be realized in numerous cases on account of the constitution of many consumable items, such as non-transparent test strips, for example. A reflective illumination of the optical codes is also ruled out for many medical systems since the available structural space in the case of the known systems and illumination techniques, does not allow the area of the optical code to be sufficiently illuminated.
Therefore, it is an object of the present invention to provide a medical system which at least substantially avoids the disadvantages of the medical systems described above. The medical system is intended to enable a reliable, structural-space-saving and cost-effective exchange of information between at least one medical consumable item and a medical device of the type described above.